cs5378 Cirrus Logic, Inc., cs5378 Datasheet - Page 20

• Manufacturer Part Number: cs5378
• Description: Low-power Single-channel Decimation Filter
• Manufacturer: Cirrus Logic, Inc.

4. POWER SUPPLIES
The CS5378 has three sets of power supply inputs.
One set supplies power to the I/O pins of the device
(VDDPAD), another supplies power to the logic
core (VDDCORE) and the third supplies power to
the PLL (VDDPLL). The I/O pin power supplies
determine the maximum input and output voltages
when interfacing to peripherals, the logic core pow-
er supply largely determines the power consump-
tion of the CS5378 and the PLL power supply
powers the internal PLL circuitry.
4.1 Pin Descriptions
VDDPAD, GNDPAD - Pins 9, 10
Sets the interface voltage to a microcontroller, sys-
tem telemetry, modulator, and test DAC. VDD-
PAD can be driven with voltages from 3.3 V to
5 V.
VDDPLL, GNDPLL - Pins 15, 16
Sets the operational voltage of the internal CS5378
PLL circuitry. Can be driven with voltages from
3.3 V to 5 V.
DS639F1
GNDPAD
VDDPAD
Figure 10. Power Supply Block Diagram
1
2
3
4
5
6
7
8
9
1 0
1 1
1 2
1 3
1 4
VDDCORE, GNDCORE - Pins 21, 22
Sets the operational voltage of the CS5378 logic
core. VDDCORE can be driven with voltages from
2.5 V to 5 V. A 2.5 V supply will minimize total
power consumption.
4.2 Bypass Capacitors
Each power supply pin should be bypassed with
parallel 1 µF and 0.01 µF caps, or by a single
0.1 µF cap, placed as close as possible to the
CS5378. Bypass capacitors should be ceramic
(X7R, C0G), tantalum, or other good quality di-
electric type.
4.3 Power Consumption
Power consumption of the CS5378 depends prima-
rily on the power supply voltage of the logic core
(VDDCORE) and the programmed digital filter
clock rate. Digital filter clock rates are selected
based on the required output word rate as explained
in “Digital Filter Initialization” on page 38.
2 8
2 7
2 6
2 5
2 4
2 3
2 2
2 1
2 0
1 9
1 8
1 7
1 6
1 5
GNDCORE
GNDPLL
VDDCORE
VDDPLL
CS5378
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